Poster: The Evolution of the Galaxy Cluster Red Sequence at Intermediate Redshift

Poster: Properties in llustris Galaxies in Observer's Phase Space

Thorsten Lisker

We doubt that the present-day environment alone yielded the morphology-density relation and set the properties of dwarf galaxies. Instead, we propose that more quantitative comparisons of simulations and observations be done and that all possible hypotheses be explored for when and why the dwarfs acquired their characteristics.

Josefina Michea

Under the ΛCDM paradigm of hierarchical structure formation, galaxy clusters progressively build-up as the Universe ages. This assembly process is imprinted in the evolving properties of the galaxy cluster red sequence across redshift space.

Christoph Engler

Characteristics such as age, metallicity and time of infall are reflected in the kinematic properties of galaxies.

Linda Urich

Ram pressure stripping models predict colour gradients that are similar to those we observe in early-type dwarf galaxies. A fraction of them includes a young central stellar population, while almost all of them have a non-zero metallicity gradient. Urich et al. 2017

Talk:Were the most compact and most diffuse stellar systems in galaxy clusters both formed by stripping?

Carolin Wittmann

Wittmann et al. 2016: Spatial distribution of spectroscopically confirmed compact stellar systems (grey and red dots) in the Fornax cluster. Compact objects with an asymmetric or elongated outer structure are preferentially located at larger cluster-centric distances, similar to low-mass galaxies (blue crosses). This might be an indication that some of these are the remnant nuclei of tidally stripped galaxies.

Wittmann et al. 2017:Faint low surface brightness galaxy candidates in the Perseus cluster core (red dots and left side panels). The majority of the sample does not show obvious signs of ongoing tidal distuption. The sample is superimposed on our deep V-band mosaic (WHT/PFIP) that we used for their identification.

Correlations between age/metallicity colours and colour gradients: A young stellar population in the galaxies centres leads to a stronger age gradient, while a metal-enriched central region does not necessarily imply a metallicity gradient. See also Urich et al. 2017

Poster by T. Lisker: How can we decide which galaxy properties were set at birth and which by environmental transformation?

Bialas et al. 2015:N-body simulations of galaxy harassment.The figure shows how much energy (colour scale) is approximately injected into the stellar component of the galaxy by a close approach of a massive cluster galaxy, depending on the distance of closest approach (x-axis) and the relative velocity (y-axis).